Files with the XLM extension are associated with Excel, a spreadsheet creator and editor developed and sold by Microsoft. Compatible with multiple operating systems, it's currently the number one software in the world for creating and editing spreadsheets.

Microsoft Excel stores data in worksheets. Each worksheet has a grid of cells arranged in columns and rows. Cells can contain text and numbers of various fonts, colors and sizes. Spreadsheets may also include charts, pivot tables, graphs and mathematical functions.

Microsoft Excel also offers macro support. Excel Macros can be created with the Recorder included in MS Office which can save command sequences and store them in macros that replicate them automatically. The Recorder can be accessed from the Tools menu. Every time a Macro is created, it is saved in a separate XLM file. Keyboard shortcuts can also be assigned for each macro.